Device for controlling electric circuits



Jan. 2, 1945. c. o. WOOD 2,366,305

DEVICE FOR CONTROLLING ELECTRIC CIRCUITS Filed Oct. 3, 1942 INVENTOR. /2 C1400; 0. [1 009 A T TOR/V5 Y Patented Jan. 2, 1945 DEVICE FOR CONTROLLING ELECTRIC CIRCUITS Claude 0. Wood, Chicago, 111., assignmto Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Application October 3, 1942, Serial No. 460,623

9 Claims.

This invention relates to improvements in devices for controlling electric circuits.

The principal objects of my invention are to provide a novel form of time delay relay which is of a simplified, improved, and more efflcient construction than formerly.

A more specific object of my invention is to provide a relay or contactor including an armature adapted to make and break an electric contact, with a. single spring for moving said armature in a position to close an electric contact and an electromagnet for moving said armature in a position to open said electric contact, together with a simplified and improved mounting for said armature for reducing sticking and burning between the contacts of the relay as the electric circuit controlled thereby is opened and closed.

A further object of my invention is to provide a time delay relay with a gap-spacing or time delay element formingthe magnetic gap, which is of a relatively large cross sectional area, and to so locate said gap-spacing element that it will not be subject to Wear or oxidation, to eliminate variations in the timing due to wear and oxidation of said gap-spacing element.

Other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawing wherein:

Figure 1 is an isometric view of a time delay relay constructed in accordance with my invention, with certain parts broken away and shown in section;

Figure 2 is a view in side elevation of the device shown in Figure l with certain parts shown in longitudinal section;

Figure 3 is a fragmentary sectional view taken substantially along line 33 of Figure 1;

Figure 4 is a top plan view of the relay shown in Figure 1, with certain parts broken away and certain other parts shown in horizontal section; and

Figure 5 is a bottom plan view of the relay shown in Figure 1, with certain parts broken away and certain other parts shown in horizontal section.

Referring now in particular to the drawing and the simplified form of electromagnetic time delay relay of my invention, a magnetic structure is provided which includes a core l0 mounted at one of its ends in a support member H, and projecting outwardly from said support member. Said support member is secured to an insulating board l2 by means of suitable machine screws and said core and support member may be made from a suitable form of magnetic iron, such as low carbon iron, known to the trade as Swedish" or Armco iron. Said support member extends upwardly along said insulating board and then turns outwardly therefrom in a direction which in Figures 1 and 2 is shown as being a horizontal direction, and has a retaining clip l3 mounted on its outer end, which is adapted to engage the outer end of and retain a wound electric coil M on said core. Said coil forms a winding for the electromagnetic structure and is mounted on an insulating sleeve l5, which is mounted on and encircles a sleeve l6 mounted on the core in.

The sleeve l6 may 'be made from copper or any other material of high electrical conductivity and serves as a short circuited winding, to cause a slow decay of the flux in the core In, so that an armature is may be held against the core 10 for an appreciable period after the electrical circuit in the magnetizing coil is cut off, in a manner well known to those skilled in the art.

The armature I9 is provided with an electrical contact 20 on the lower end thereof, which is adapted to be engaged with a stationary contact 2| to complete an electrical circuit. Said stationary contact is mounted onan upright support member 22, which is secured to the end of a bracket 23, which also serves as an electrical conductor.

Referring now in particular to certain novel features of my invention and the simplified mounting of the armature IS on the support It, so the electric contacts 20 and 2| will be disengaged with a rolling action, said armature is herein shown as being a fiat widened piece of metal and is preferably made from a magnetic iron such as low carbon iron, known to the trade as Swedish or Armco iron. A pair of slots 24, 24 are formed in said armature adjacent the upper end thereof. Said slots open to opposite sides of said armature and engage opposite sides of a U-shaped member 25, preferably made from a non-magnetic material. Said U-shaped member is secured to the outer end of a supporting strip 26, which is mounted on the upper side of the support ll and which projects outwardly therefrom. The spaces between the end of said supporting strip and the inside of the open portion of the U of said U-shaped member form a slot along which said armature is movable, which is of such a length as to permit rectilinear movement of said armature therealong in the direction of the longitudinal axis of the core 10, when moved to engage or disengage the electric contacts.

A spring 21 having connection with the lower end of the armature I8 is provided to move said armature l9 and the contact 20 to a position to engage the contact 2|. Said spring, as herein shown, encircles a threaded pin 28 mounted on said armature and extending outwardly therefrom through an enlarged aperture formed in the bracket 22. Said spring is interposed between the outer end of said bracket and a washer 29 on said pin, and is held adjacent the outer end thereof by means of nuts 30, 30, which form a means for adjusting the tension of said spring.

It may be seen from the foregoing that when the core I is demagnetized, the spring 21 will move the armature along the slot formed by the end of the support strip 26 and the inside of the U-shaped member 25, in a direction to engage the contact with the contact 2 I, and that this movement will be a substantially rectilinear movement. When, however, the coil II is energized, the electromagnet will attract the armature l9, and due to the reaction of the spring 21 against the lower portion of said armature, will first slide the upper end of said armature towards the core Hi and will then move the lower end of said armature to disengage the contact 20 from the contact 2|. This will cause a rolling disengaging action of said contacts and will prevent the contacts from sticking as the electrical circuit therebetween is broken.

Referring now in particular to the means for providing a definite gap in the magnetic circuit, to determine the extent of the delay in the decay of the magnetic flux of said armature, said gap is attained by means of a shim 34. Said shim may be made from any form of non-magnetic material and is secured to the upper surface of the support II and spaces the supporting strip with respect to said support, to magnetically isolate said supporting strip from said support, it being understood that the screws securing said supporting strip to said support are also made from a non-magnetic material, such as brass. Thus, when the armature is magnetically moved to the attracted position, the shim 34 will insure that there will be a definite and invariable gap between the members II and 25. Adjustment of the time element may be obtained by interchanging said shim with either thicker or thinner shims as the case may be; the thinner the shim, the longer will be the element of time delay.

The shim 34 is so positioned that it may be of a relatively large area, compared with former elements for providing a gap in a magnetic circult; thus thicker shims may be utilized than formerly, making it possible to more accurately adjust the timing. It should here be noted that it has heretofore been impossible to obtain a thin enough shim to provide the required timing in many cases, and that the device of the present invention makes it possible to provide the desired timing by so arranging the relay that a shim of larger area than formerly may be provided, without increasing the size of the parts of the relay, so the required time delay may be attained by using a thicker shim than was formerly possible for the same time interval of delay attained by the thinner shims,

It may be seen from the foregoing that the shim 34 is of a large cross sectional area and is clamped between stationary parts of the relay, thus eliminating variations in timing due to wear and oxidation. It may also be seen that more accurate time adjustments may be made, due in the increased area of the magnetic gap, and that the interchanging of shims of greater or lesser thickness so as to change the time interval of operation of the relay, will have no effect on the location or operation of the armature ll, to open or close the electrical circuit.

While I have herein shown and described one form in which my invention may be embodied, it will be understood that the construction thereof and the arrangement of the various parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be construed as limiting my invention to the specific embodiment illustrated, excepting as it may be limited in the appended claims.

I claim as my invention:

1. In an electromagnetic relay, a projecting supporting strip having a slotted outer end, an electromagnet spaced from said supporting strip, a stationary contact spaced on the opposite side of the core of said magnet from said supporting strip, an armature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, and a loose supporting connection between the slotted forward end of said supporting strip and said armature, to cause said magnet to disengage said contacts with a rolling action.

2. In an electromagnetic relay, a supporting strip, an electromagnet spaced from said supporting strip, a stationary contact, an armature having a contact thereon adapted to engage said stationary contact, a single yieldable member having connection with said armature adjacent its lower end, for moving said armature away from said electromagnet and for engaging said contacts, and a loose and sliding connection between said supporting strip and armature, to cause said electromagnet to disengage said contacts against said yieldable member with a rolling action.

3. In an electromagnetic relay, a projecting supporting strip having a slotted outer end, an electromagnet disposed beneath said supporting strip, a stationary contact disposed beneath the core of said magnet, an armature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, a single spring having connection with said armature, for moving said armature away from said electromagnet, to engage said movable contact with said stationary contact, said armature extending through and depending from the slotted portion of said supporting strip and being loosely mounted thereon, for horizontal sliding and rockable movement with respect thereto.

4. In an electromagnetic relay, a projecting supporting strip having a slotted outer end, an electromagnet disposed beneath said supporting strip, a stationary contact spaced from the core of said magnet, an armature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, yieldable means for moving said armature in a direction away from said electromagnet, for engaging said stationary contact with said movable contact, and said armature being mounted to loosely extend through said slotted forward end of said supporting strip and having portions engaging the side of said supporting strip opposite from said armature, for loosely and rockingly supporting said armature on said strip so said magnet may move said armature along said strip and at the same time pivot said armature, to disengage said contacts with a rolling action.

5. In an electromagnetic relay of the class described, an insulating board, a member constructed from a magnetic material, secured to said board and having a leg projecting from said board, an electromagnet secured to the portion of said member secured to said board and projectin outwardly therefrom in the same direction as said projecting leg, a supporting strip secured to said projecting leg of said member and projecting therefrom and magnetically insulated from said projecting leg, an armature supported on said supporting strip and adapted to be attracted by said magnet, a stationary electrical contact, an electrical contact on said armature, a single spring acting on said armature for moving said armature away from said electromagnet, to engage said movable contact with said stationary contact, and said supporting connection between said supporting strip being loose and rocking, to cause said magnet to disengage said contacts against said spring with a rolling action.

6. In an electromagnetic relay, a horizontally extending supporting strip having a slotted forward end, an electromagnet disposed beneath said supporting strip, a stationary contact disposed beneath the core of said magnet, an armature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, a loose supporting connection between the slotted forward end of said supporting strip and said armature, and a single spring for engaging said movable contact with said stationary contact and reacting against said armature during disengagement of said contacts to cause said magnet to disengage said contacts with a rolling action.

7. In an electromagnetic relay, 0, horizontally extending supporting strip having a slotted forward end, an electromagnet disposed beneath said supporting strip, a stationary contact disposed beneath the core of said magnet, an armature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, a single compression spring having connection with said armature adjacent its lower end,,'for moving said armature away from said electromagnet. to engage said movable contact with said stationary contact. said armature extending through and depending from the slotted portion or said supporting strip and being loosely mounted thereon, for horizontal sliding and rockable movement with respect thereto.

8. In an electromagnetic relay, a horizontally extending supporting strip having a slotted forward end, an electromagnet disposed beneath said supporting strip, a stationary contact disposed beneath the core of said magnet and spaced outwardly therefrom, anarmature having a contact thereon, adapted to engage said stationary contact and be disengaged therefrom by said magnet, a single yieldable member for moving said armature in a direction away from said electromagnet, for engaging said stationary contact with said movable contact, and, said armature being mounted to loosely extend through and depend from said slotted'forward end of said supporting strip and having portions resting on opposite sides of the upper end thereof, for loosely and rockingly supporting said armature on said strip so said magnet may move said armature along said strip and at the same time pivot said armature, to disengage said contacts against said yieldable member with a rolling action.

9. In an electromagnetic relay of the class described, a vertically extending insulating board, a member constructed from a magnetic material, secured to said board and having a leg projecting horizontally from said board, anvelectromagnet secured to the vertical portion of said member .and projecting outwardly therefrom in the same direction as said horizontal leg, a supporting strip secured to the horizontal leg of said member and projecting therefrom and magnetically insulated from said horizontal leg, an armature mounted on and depending from said supporting strip and adapted to be attracted by said magnet, a stationary electrical contact, an electrical contact on said armature, a single spring acting on the lower portion of said armature for moving said armature away from said electromagnet, to encause said magnet to disengage said contacts against said spring with a rolling action.

CLAUDE O. WOOD. 

